BST 290 Seminar: Bruce Rannala

BST 290 Seminar Series

Title: Bayesian species delimitation and species tree inference using genome sequence data

Abstract: Genomic sequence data are taking on new importance in systematics, both for the identification (delimitation) of species and for inferring the phylogenetic relationships among species. A method is described for simultaneous Bayesian inference of species delimitation and species phylogeny from multi-locus sequence data using the multi-species coalescent model. Simulation results suggest that the method tends to be conservative with high posterior probabilities being a confident indicator of species status. Simulations also indicate that the power of the method to delimit species increases with an increase of the divergence times in the species tree and an increased number of gene loci. Re-analyses of two datasets of cavefish and coast horned lizards suggest considerable phylogenetic uncertainty even though the data are informative about species delimitations. The impact of the prior on models of species delimitation and species phylogeny on Bayesian species delimitation are discussed.